When designing a package, one of the most important features is the package's ability to attract the attention of the shopper. Since most products are displayed on the retailer's shelf, the package must be able to catch the eye of the potential buyer by distinguishing your product's package from the others. This is usually accomplished by using a colorful label or a colorful and unique packaging material.
U.S. Pat. No. 6,020,823 discloses a package wrap for decoratively covering a container having sidewalls. A flexible thin sheet of polymeric material is adapted to be shrink-wrapped onto the exterior walls of the container. An illuminating device is positioned between the flexible thin polymeric sheet and the exterior of the container so that when the polymeric sheet is shrink-wrapped onto the container the illuminating device will be held securely in place.
U.S. Pat. No. 2,634,530 discloses an illuminated sign where the edge of the sign is illuminated.
U.S. Pat. No. 5,852,514 (Toshima et al.) describes a light-diffusing element comprising a light diffusion layer including acrylic resin and spherical particles of polymethyl methacrylate on a transparent support. Whereas this film would diffuse the light efficiently, the polymers used have high glass transmission temperatures and would therefore be difficult to melt the spherical particles completely to create areas of specular transmission. When illuminated these not completely melted lenses would diffuse a portion of the light lowering the brightness of the printed, more specular areas and thus lowering contrast of the overhead illuminated image.
U.S. Pat. No. 5,369,419 (Stephenson et al.) describes a thermal printing system where the amount of gloss on a media can be altered. The method uses heat to change the surface properties of gelatin, which has many disadvantages. Gelatin cannot achieve high roughness averages, thereby having a low distinction between the matte and glossy areas of the media. This small distinction between the matte and glossy states leads to a low signal to noise ratio and when illuminated, creates lower contrast ratios. Gelatin also is very delicate, scratch prone, and self-healing, and so it tends to flow over time thus changing its surface roughness and other properties with time especially in high humidity and heat, and is dissolved if placed in water. Also, gelatin has a native yellow color, is expensive, and is tacky, sticking to other sheets and itself. It would be desirable to use a material that had no coloration, is more stable in environmental conditions, and could have a higher surface roughness.
When businesses advertise, they use colorfully lighted signs to attract the attention of customers. It would be very advantageous to be able to have individual packages light up in a similar fashion to a colorfully lighted sign. The problem is the ease adding this feature to existing packages. One can add illuminated devices and miniature lights to the package but these require power sources and are relatively expensive. These are also fragile and susceptible to damage.
Another technique used to illuminate products such as liquids in translucent bottles is to place these on a lighted shelf and use the transmissive properties of the light and the bottle to illuminate the product.
The problem with existing packaging is that it is not easily and inexpensively illuminated other than shinning a light directly on the package, which does nothing to distinguish it from its neighbor. The same is true for placing bottled products on a lighted shelf.
To solve the problems of the prior art what is need is a packaging material that can pipe light from a lighted surface to selectively illuminate portions of a package. Using light diffusing elements that are flattened with exposure to heat and/or pressure, a high contrast image can be obtained where the printed areas (flattened light diffusing elements) are bright and the non-imaged areas are dark. This increased contrast between the printed and non-printed areas allows portion of the package containing the printed material to be brightly illuminated. Not only can the imaged areas be bright, but they can also be colored producing projected images of text, images, shapes, and pictures with many colors on a darker background.